In this post I wrote about my gap filling tests. I decided to go with the resin/mortar combination. I ordered some resin from Screw-fix because it is relatively cheap and because I had spoken with a structural engineer last summer and he had recommended it. The problem is, it comes in a proprietary tube that doesn't fit in a regular caulking gun. I had already decided that I would make a custom tool to help me apply it to the bricks, but I never imagined the tool would require so much effort to make. Here's what I've come up with. It is based on the same principle as the clay extruder I made last fall. The first problem was the extreme amount of pressure that is applied to the pieces. Initially, the notches on the vertical post were pieces that I attached with screws, but the force of the bar was ripping them out. So instead, I notched out the post itself. As well, the plate where the tube rests had to be re-anchored with extra support. The second problem was the ...